package jdbc;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/*
* 预编译SQL语句
* 当SQL语句中需要含有用户提供的数据时，为了避免因为拼接SQL导致语义发生改变（SQL注入攻击）
*
* */
public class JDBCDemo7 {
    public static void main(String[] args) {
        UserInfo userInfo = InputUtil.getInputObject(new UserInfo(),"欢迎登录","登录");
        try (
                Connection connection = DBUtil.getConnection();
                ){
            String sql = "SELECT id,username,password,nickname,age "+
                    "FROM userinfo "+
                    "WHERE username=? AND password=?";
            PreparedStatement ps = connection.prepareStatement(sql);
            ps.setString(1, userInfo.getUsername());
            ps.setString(2, userInfo.getPassword());
            //密码：asd' OR '1'='1
            ResultSet rs = ps.executeQuery();
            if(rs.next()){
                System.out.println("登录成功");
            }else {
                System.out.println("登录失败");
            }

        } catch (SQLException e) {
           e.printStackTrace();
        }
    }
}
